Communication system, node, packet forwarding method and program

Abstract

Even though the number of communication terminals or that of communication services exploited by the communication terminals is increased, load imposed on a node or a controller is to be less likely to be increased, while delay in processing is to be less likely to be produced. Each node of a communication system holds a plurality of packet handling operations which correlate the forwarding destination of a packet belonging to each flow with a set of collation rules that identify each flow, and forwards the received packet in accordance with the processing rules. In case the destination address of the received packet is such address indicating that the packet is to be multicast, the node multicasts the packet using the plurality of the processing rules the node holds.

1 . A communication system, comprising a node holding a plurality of packet handling operations which correlate the forwarding destination of a packet belonging to each flow with a set of collation rules that identify each flow; the node forwarding the packet received in accordance with the packet handling operations; wherein,
 in case the destination address of the received packet is such address indicating that the received packet is to be multicast, the node multicasts the packet using the plurality of the packet handling operations the node holds.   
     
     
         2 . The communication system according to  claim 1 , wherein,
 the node includes a packet handling operation retrieving condition producing unit that produces retrieving conditions which will extract the packet handling operations matched to a destination of multicasting; and wherein,   in case the destination address of the received packet is an address indicating that the received packet is to be multicast, such packet handling operations including collation rules matched to the retrieving conditions produced by the packet handling operation retrieving condition producing unit are extracted to execute multicast-forwarding.   
     
     
         3 . The communication system according to  claim 1 , wherein,
 in case the destination address of the received packet is a link local multicast address, the packet handling operation retrieving condition producing unit produces the retrieving conditions which will extract the packet handling operations including the collation rules in which a Layer 3 destination address coincides with a Layer 3 network address of the source of packet transmission.   
     
     
         4 . The communication system according to  claim 1 , wherein,
 in case the destination address of the received packet is a direct multicast address, the packet handling operation retrieving condition producing unit produces retrieving conditions which will extract packet handling operations including collation rules in which the Layer 3 destination address coincides with a Layer 3 network address of the destination.   
     
     
         5 . A node, holding a plurality of packet handling operations which correlate the forwarding destination of a packet belonging to each flow with a set of collation rules that identify each flow; the node forwarding the received packet in accordance with the packet handling operations; wherein,
 in case the destination address of the received packet is such address indicating that the packet is to be multicast, the node multicasts the packet using the plurality of the packet handling operations the node holds.   
     
     
         6 . The node according to  claim 5 , comprising a packet handling operation retrieving condition producing unit that produces retrieving conditions which will extract the packet handling operations matched to a destination for multicasting; wherein,
 in case the destination address of the received packet is an address indicating that the received packet is to be multicast, such packet handling operations including collation rules matched to the retrieving conditions produced by the packet handling operation retrieving condition producing unit are extracted to execute multicast-forwarding.   
     
     
         7 . The node according to  claim 5 , wherein,
 in case the destination address of the received packet is a link local multicast address, the packet handling operation retrieving condition producing unit produces the retrieving conditions which will extract the packet handling operations including the collation rules in which a Layer 3 destination address coincides with a Layer 3 network address of the source of packet transmission.   
     
     
         8 . The node according to  claim 5 , wherein,
 in case the destination address of the received packet is a direct multicast address, the packet handling operation retrieving condition producing unit produces retrieving conditions which will extract the packet handling operations including the collation rules in which a Layer 3 destination address coincides with a Layer 3 network address of the destination.   
     
     
         9 . A method for forwarding a packet at a node holding a plurality of packet handling operations which correlate the forwarding destination of a packet belonging to each flow with a set of collation rules that identify each flow; the node forwarding the received packet in accordance with the packet handling operations;
 the method comprising:   confirming whether or not a destination address of the received packet is an address indicating that the received packet is to be multicast; and   multicast-forwarding the packet, using the plurality of packet handling operations, in case the destination address of the received packet is an address indicating that the received packet is to be multicast.   
     
     
         10 . (canceled) 
     
     
         11 . The communication system according to  claim 2 , wherein,
 in case the destination address of the received packet is a link local multicast address, the packet handling operation retrieving condition producing unit produces the retrieving conditions which will extract the packet handling operations including the collation rules in which a Layer 3 destination address coincides with a Layer 3 network address of the source of packet transmission.   
     
     
         12 . The communication system according to  claim 2 , wherein,
 in case the destination address of the received packet is a direct multicast address, the packet handling operation retrieving condition producing unit produces retrieving conditions which will extract packet handling operations including collation rules in which the Layer 3 destination address coincides with a Layer 3 network address of the destination.   
     
     
         13 . The communication system according to  claim 3 , wherein,
 in case the destination address of the received packet is a direct multicast address, the packet handling operation retrieving condition producing unit produces retrieving conditions which will extract packet handling operations including collation rules in which the Layer 3 destination address coincides with a Layer 3 network address of the destination.   
     
     
         14 . The node according to  claim 6 , wherein,
 in case the destination address of the received packet is a link local multicast address, the packet handling operation retrieving condition producing unit produces the retrieving conditions which will extract the packet handling operations including the collation rules in which a Layer 3 destination address coincides with a Layer 3 network address of the source of packet transmission.   
     
     
         15 . The node according to  claim 6 , wherein,
 in case the destination address of the received packet is a direct multicast address, the packet handling operation retrieving condition producing unit produces retrieving conditions which will extract the packet handling operations including the collation rules in which a Layer 3 destination address coincides with a Layer 3 network address of the destination.   
     
     
         16 . The node according to  claim 7 , wherein,
 in case the destination address of the received packet is a direct multicast address, the packet handling operation retrieving condition producing unit produces retrieving conditions which will extract the packet handling operations including the collation rules in which a Layer 3 destination address coincides with a Layer 3 network address of the destination.